Two stage hammer mill



July 22, 1947.

H. M. JOHNSTON Two STAG-E HAMMER MILL 4 Sheets-Sheet 1 Filed Feb. 23, 1945 v VIVINVENTOR. p I Howgm JOHNSTON BY" 'Affqm/EY 4 Sheets-Sheet 2 H. M. JOHNSTON TWO STAGE HAMMER MILL Filed Feb. 23, 1945 July 22, 1947.

-, INVENTOR.

' HGWARQ MJH/vsTo/v Afromvsr July 22, 1947. H. M. JOHNSTON 'rwo STAGE HAMMER MILL Filed Feb. 23, 1945 4 Sheets-Sheet 5 INVEN TOR N. JOH 570/v HOW/1R0 y 1947- H. M. JOHNSTON TWO STAGE HAMlfIER MILL Filed Feb. 25, 1945 4 Sheets-Sheet '4 IN VEN TOR. How/a RZ/ISVADIOHNS 7017' BY 1d A T'T'OR'N E Y Patented July 22, 1947 TWO STAGE HAMIHER MILL Howard Milton Johnston, Toronto, Ontario, Can'- ada, assignor to Massey-Harris Co. Ltd., Toronto, Ontario, Canada, a corporation of Canada Application February 23, 1945, Serial No. 579,359

2 Claims. 1

This invention is an improved feeding attachment for the design shown and described in my co-pending application, Serial No. 484,353, filed April 24, 1943, maturing into Patent #2,376,361, May 22, 1945, and it is the intention that the present patent shall cover by suitable expression in the appended claims, features of patentable novelty other than claimed in said Patent #2376361.

The present invention relates to a grinding mill of the hammer type and an object of the invention is to provide a mill that will deliver a more uniformly ground Product,

Still another object of my invention is to provide a mill which can be made largely of sheet or bar stock and having a larger capacity than' other mills of the same size, weight and cost.

A further object of my invention is to provide a mill through which the material flows largely on easy single curved paths, thus to avoid a slowing down of the material because of trenches, pockets, ledges or unnecessary sharp or reverse turns.

Another object of my invention is to provide a mill in which the ground particles may pass through the screen any place within the 360 diameter of the screen. I

Another object of my invention is to provide an auxiliary air inlet for use largely when grinding grain, in orderto give the operator better control over the grinding operations.

An object of the present invention is to provide a mill which can be made in very small or very large sizes without detracting from its utility which is commensurate with its capacity.

Important objects of the present invention are to provide, what I term, a crusher adjacent the feed-in opening to the mill, to thereby better prepare roughage for grinding and to act as a. governor to better distribute the material as it enters the mill and generally increase the capacity and efficiency of the mill.

To these and other useful ends my invention consists of parts, combinationsof parts or their equivalents and mode of operation as hereinafter described and claimed and shown in the accompanying drawings in which:

Fig. 1 is a side elevational view of my improved mill with the access lid lifted, in this figure the crusher unit is not shown.

Fig. 2 is a sectional view taken on line 22 of Figure 1, the crusher unit is shown in this figure and sectioned on the same line as lines 2-2 of Figure 1.

Fig. 3 is a sectional view taken on line 33 of Figure 2.

'Fig. 4 is a reduced side elevational view of my improved device, with the crusher housing sec- Fig. 6 is a side elevational view of the air inlet to the crusher chamber.

Fig. 7 is a side view of the air inlet as shown in Figure 6. I

In the figures the grinder housing is, in its entirety, designated by reference character A and the rotor is, in its entirety, designated by. refer-- ence character B. Member A comprises side' panels I0 and II and an outer wall I2 which terminates as at I3 and I4. Sidepanels I0 and II are cutaway on lines I5 and I6.

A lid which, in its entirety is designated by reference character C, is formed by means of side plates I1 and I8 and a cover I9 which is hinged to member I2 as at 20. When lid C is closed; as

illustrated in Figure 3, means (not shown) is pro vided for locking the lid in its closed position at l3. Members II), II, I2, I1, I8 and l9scomplete the housing member. I

Members I 0, II, I1 and I8 are cut-away so as to 'form concentrically positioned openings 26-26. ,Bearings Hand 28 (see Figure 2) are rigidly secured to members I0 and II concentrically with openings 25. A shaft 3| is rotatably mounted in bearings 21 and 28 as illustrated, the shaft at one end protruding through bearing 28 and havingmeans secured to this end,

preferably a suitable pulley, for drivin the shaft.

Member B comprises a hub 35 made from a number of collars and positioned'on shaft 3| and keyed thereto in a manner clearly illustrated in Figure 2. I provide a supplemental partition 36- which is circular and terminates at its periphery as at 38. This partition is held in position to member Ill by 3 Z-shaped brackets 34,rwhich are positioned over the screen joints as shown by dotted lines in Figure 1.

I provide a removable screen preferably formed in three parts, 39, 40 and 4| andbeing. secured to members I0 and 36 in a manner whereby each screen member may be removed when lid C'is lifted. These three screens are positioned by angle bars 42-42 which are secured to members I0 and 36 providing a rotor chamber 43and an annular chamber 44.

Annular chamber 44 is interconnected with the space formed by members l, i8 and 36. I mount a fan blade carrying member 45 on hub 35, this member having preferably three arms 46 secured thereto which extend to within a short distance of members I! and I9 (see Figure 2). On each arm I mount a booster or fan blade 41, the blades extending into chamber 44 about as shown in Figure 2. I mount of number of blades 48 between the hub collars 35, the hub thus formed and members 48 being preferably keyed to shaft II and made taut by means of end nuts 49-49. In addition to keying at least one hub collar 85 to the shaft, I preferably supply dowel pins 50. These pins extend through members 48 for locking these members and the hub collars together.

I have shown three members 48 positioned as illustrated in Figures 2 and 3 through which the shaft extends.

I provide preferably two wearing plates 55 on the ends of members 48. These plates are made removable and reversible so when the corners become badly worn. they may be turned for wear on the other corner and when both corners at one end are badly worn; then they may be reversed so the other ends of these plates will be serviceable. I provide a feed and air outlet 56 from chamber 44, which is shaped and positioned about as shown in Figures 1 and 3.

I will now describe my improved crusher-feed mechanism as illustrated in Figures. 2, 4, 5, 6 and 7. Housing panel I is provided with an opening 88 which extends from hearing 21 to angle bar 42 (seeFigure 2) and being curved at its bottom to correspond with the curve of the angle bar and having a width preferably somewhat narrower than the width of the crusher housing which comprises a bottom member 8|,

trough comprising a plate 10, which is hinged to the bottom of-the trough as at 1| and having side members 12; thus when the end-gate is in the position shown by full lines the trough is suitable for feeding grain to the mill and when the end-gate is in the position shown by dotted lines the trough will be suitable for feeding roughage and fodderto the mill. I provide a guard 19 in the outlet end of the trough for assisting the roughage to enter the crushing chamber 89 and protect the operator from contact with the crusher blades. regulating the'flow of grain into the crusher chamber.

I provide an air inlet opening to the crusher chamber as'follows:

An opening II is cut into the end wall 88 of the crusher chamber and a three sided V-shaped member" fits around this opening having an opened top as at 89, and a lid 84 which is hinged as at 84 with preferably a thumb nut 85 adapted=toihold the lid in any desired position, so the lid may be set to permit more or less air to enter the crusher chamber while grinding grain.

When grinding roughage lid 84 is generally closed because generally plenty of air is permitted to enter with the'roughage which insures perfect operation of the-mill. Openin 8| is ap- I provide a gate valve 14 for I provide a proximately in line with shaft SI for a purpose which is obvious.

The screens 39, 48 and 4| are preferably the same length, the ends meeting at points 41, see Figure 3. At these points one edge of each screen is furnished with a relatively thin strip 88 the free ends of which he ever the joint between the screens and extend inwardly slightly as illustrated. These strips are very thin however they actto move the fast moving feed particles inwardly so as to make plates 88 more eillcient. Clearly any detachable means may be used for holding the screen snugly against angle bars 42.

It will be seen that in the present design a partial vacuum will be set up by the action of blades 41 and that this vaccum will cause air to be drawn into the crusher chamber through opening 68 when roughage is being ground and through opening 8| when valve 84 is open for grinding grain. Blades 41 will act to draw the feed particles through the screen as soon as they are small enough to pass through the openings in the screen and will discharge the ground feed and air into outlet 56. Clearly therefore the air and feed will travel through the machine in easy single curves so there will be no place within the machine where the material will be retarded in its direct travel through the machine.

Furthermore there is no pocket or ledge for the ground material to lodge in or on, so that the material will be swept from the screen by blades 41 immediately it passes through the openings in the screen.

For the smaller sized machines I provide four suitably shaped legs 18 as supports.

I will now describe the crusher mechanismy shaft 3| is elongated for. about the width of the crusher housing as illustrated 'in Figure 2. I provide a-number of sleeves 90 and mount between each of thesesleeves a crusher bar 8|, the

sleeves being held against the blades by means of nut 92. The bars and sleeves are preferably keyed (not shown) to the shaft and arranged around the shaft as illustrated in Figures 4 and. 5. I mount a number of retarding blades 98 on into chamber 43. For example when an excessively large bundle of roughage enters the crusher chamber, because of the direction bars 9| are turning, the roughage will to some extent be held in suspension in the top of the crusher chamber and in front of and on blades 98 until it is torn apart and crushed, after which it will ilow in a more evenly distributed mass into chamber 48.

It will be seen by viewing Figure 2 that immediately the roughage is torn apart and more or less broken or crushed it will fall on member II and flow into the mill by gravity assisted by the vacuum in chamber 48; and that the material after passing into the grinding chamber will make a circular turn or turns until it passes into outlet 88. This circular movement is caused by.

rotor B and fan blades 41, each turning in the same direction and close to opposite sides of the screen. i

Clearly the action of fan blades 41 and members 55 will be to prevent the screens from clogging, thus to add to the capacity and efficiency of the mill.

While I have shown and described the preferred'embodiment of my invention, clearly the invention is not limited to that particular construction but includes such variations or modifications as would occur to those skilled in the art.

Having thus shown and described my invention, I claim:

1. A mill of the character described; comprising a main housing, a shaft rotatably mounted in the side Walls of the housing having mounted thereon and within the housing a grinding rotor, said shaft protruding a distance at each end, one end having driving means mounted thereon and the other end having longitudinally and circumferentially spaced crusher bars, a circular screen within the housing radially enclosing the grinding rotor, a ground feed outlet in the housing located radially outside of the screen, a feed inlet in the side wall of the housing adjacent said crusher bars and extending a distance up from near the bottom portion of the screen, a crusher chamber surrounding said feed inlet and crusher bars, having an inlet trough in one side and at the top thereof, transversely spaced inwardly and downwardly extending retarding blades positioned in the opposite side of said crusher chamher from said trough inlet, their free ends positioned between th Paths of t e ends of said 6 crusher bars, the top of said crusher chamber being a greater distance from the path of the ends of said crusher bars than the side walls thereof, said rotor and crusher bars arranged to travel upward on the side adjacent said trough inlet, whereby said crusher bars will tend to force the roughage upwardly and rearwardly and on the top of said retarding blades.

2. A device as recited in claim 1 including, an inlet in the outer wall of said crusher chamber adjacent the end of said shaft and having an adjustable valve at its top for supplying a predetermined volume of air to the crusher chamber.

HOWARD MILTON JOHNSTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,169,684 Erickson Aug. 15, 1939 2,087,492 Williams July 20, 1937 1,440,429 William Jan. 2, 1923 2,122,658 Preston July 5, 1938 1,025,480 Pack May '7, 1912 2,298,712 Mankoif Oct. 13. 1942 1,828,490 Clement Oct. 20, 1931 FOREIGN PATENTS Number Country Date 557,228 Great Britain Nov. 10, 1943 

